Global Climate Change: The Science Behind It
Climate change is a topic that’s on everyone’s mind as of late. On TV, pundits argue about the truth of global warming, while scientists continue to come out with research that points to the increase of greenhouse gases in our atmosphere. You can’t turn around without seeing a Prius drive by, or stumbling upon a new “green” earth-friendly version of some consumer good. It can be hard to sift through all this information to get to the basic facts of global warming, so we put together this quick guide about the science behind climate change.
Carbon Dioxide and the Greenhouse Effect
Carbon dioxide, or CO2, is usually a rather harmless gas molecule. We exhale it as a result of respiration, and trees and plants inhale it to power their photosynthesis. Since the turn of the industrial revolution in the 1800s, however, the amount of CO2 in the atmosphere has risen to levels not before experienced during human existence. Carbon dioxide is put into the atmosphere as a biproduct of burning fossil fuels, that seemingly magnificent energy that made trains, cars, and factories run. Today, the concentration of CO2 in the atmosphere is at around 365 parts per million (ppm), up from 280 ppm at the turn of the 19th century. That increase of 85 ppm correlates to 3 billion metric tons of carbon being put into the atmosphere every year.
Why is this increase in carbon dioxide an issue at all? CO2 happens to be a greenhouse gas, a type of molecule that is good at insulating the earth and keeping it warm. Greenhouse gases are one of the factors that make earth livable, and keep our planet protected from the icy cold of space. When sunlight hits the earth and bounces off, molecules of CO2 (and other greenhouse gases like water, methane, and nitrous oxide) effectively trap that heat up in the earth’s atmosphere. The result is a planet with a nice, comfortable temperature that allows a range of life to exist. The problems with CO2 only begin when you start getting increasing levels in the earth’s atmosphere -- causing the earth to warm up too much.
As scientists have monitored global temperatures over the last few hundred years, they have seen a small, but significant increase in temperature. While it is difficult to show definitive correlation between these rising temperatures and the concentration of CO2 in earth’s atmosphere, most climate and atmospheric scientists believe that our use of fossil fuels is at least a contributing factor.
A Great Uncertainty
While the scientific consensus points the finger at CO2 as a contributing factor to global warming, there is much dissent about exactly how much of a factor it is. Many other variables affect global temperature, and it is difficult to do experiments to control for all of them. Even with this uncertainty, however, most scientists support the efforts to cut CO2 emissions as an effort to combat global warming, due to the large consequences that continued global warming could reek upon the earth and its inhabitants.
Source:
Global Climate Change. (2011) University Corporation for Atmospheric Research.